Furnace Buying Guide

What the best furnace has

The proper AFUE
rating. If you live in an area with harsh winters, you
should recoup the additional expense of a high-efficiency condensing
furnace (90 percent AFUE or more) over the unit's lifetime. However, if
your winters are more temperate, and you live in a state where it's
permitted, you may be better served with a furnace that has an AFUE of 80
percent. If you're unsure, have your contractor calculate fuel costs for
both kinds of furnace, using your current bills; then you can tell if
future fuel savings justify the additional $1,000 or more for a 90 percent
AFUE furnace.

Two stage valves. These control the flow of fuel so that the furnace runs high when it's
first turned on, then on a lower flow to maintain the temperature.

A
programmable thermostat. These
save energy by reducing the amount of work your furnace
must do when no one's at home. For each degree you turn down the
thermostat during an eight-hour period, you can reduce your heating bill
by about 2 percent. Programmable thermostats can keep the house at a lower
temperature when you're not home or at night. If you don't currently have
a programmable thermostat, replacing your existing thermostat is a job
most homeowners can do themselves, say experts.

Sealed
combustion. This protects your home from carbon monoxide
and is more energy efficient.

A
long warranty. The warranty on your furnace will vary
according to the manufacturer and the HVAC company and/or installer. More
efficient (and expensive) furnaces tend to have longer warranties than
basic models. With a condensing furnace, it is especially important to
have a long-term warranty on the heat exchangers.

Know before you go

Repair or
replace? Increased energy efficiency isn't
always a good reason to replace a furnace that is still in good working order.
Experts generally recommend replacing your old furnace if any of the following
apply: it's more than 15 to 20 years old; it has a pilot light rather than
electronic or hot-surface ignition; it does not have vent dampers or a draft fan;
or it is a coal-burning model that has been converted to gas or oil.

Is your home energy efficient? Before
you invest in a new heating system, experts advise improving the overall energy
efficiency of your home through steps like adding insulation and sealing air
leaks. This will reduce the heating load of your home, allowing you to purchase
a smaller furnace. You may even find that you save as much as you would if you
had purchased a more energy efficient furnace. Adding a variable-speed blower will also improve
the efficiency of your heating system and reduce wear and tear because the
furnace isn't always cycling on and off.

Do you have the right HVAC partner? It's
important to take the time to find a good HVAC professional. The contractor
should be licensed and insured, and the technician who installs the system
should be certified by North American Technician Excellence (NATE). You
should get at least three estimates in writing, and the contractor should base
the estimate on a thorough survey of your home to calculate the size of the
system you will need. Energy saving estimates should be done too, based upon
your actual energy costs and recent bills.

Are you prepared to maintain your new furnace
or boiler? Once your furnace or boiler has been installed,
proper maintenance will keep it running at top efficiency. Steps to take
include cleaning air registers and cleaning or replacing air filters in a
forced air system, and cleaning baseboards and radiators, and periodically
bleeding air, with hydronic systems. Your heating system should also be tuned
up periodically: once a year for oil-fired furnaces and boilers, once every two
years for gas-powered models. Experts say inadequate maintenance (or improper
installation) accounts for twice as many furnace problems as defective
equipment.

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